Unit Guide

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MAGNETS
UNIT OVERVIEW
agnets have the ability to pull on, or attract, certain metals because they
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exert a force called magnetism. This invisible force is caused by the electrons
in a magnet lining up in a north-south pattern. The Magnets unit helps
students discover what magnets are and how they work. Students will learn
that magnets come in many shapes and sizes, and that they have two poles.
These poles either attract or repel the poles of other magnets. Magnetic lines
of force flow out from the north pole of a magnet and back in through the
south pole. These lines of force form a powerful magnetic field around the
magnet. Students will also learn that magnetism and electricity are related.
Magnets are used for many purposes, including generating electricity,
running motors, moving large trains, lifting scrap metal, and scanning the
human body for illness. Magnets can also be found in common items, such
as toys, games, doors, cabinets, and appliances.
Certain reading resources are provided at three reading
levels within the unit to support differentiated instruction.
Other resources are provided as a set, with different titles
offered at each reading level. Dots on student resources
indicate the reading level as follows:
low reading level
middle reading level
high reading level
THE BIG IDEA
ithout magnets, our lives would be quite different. Magnets help generate
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electricity, are used in motors, and can be found in a variety of common
items. Magnets are used in medicine, industry, transportation, and other
important fields. Magnets behave in predictable ways, which makes them
reliable and valuable tools.
Other topics
This unit also addresses topics such as: large magnets can be very strong
and useful, Earth acts as an enormous magnet, magnets can work without
touching the objects they attract, and magnetism can be transferred.
SPARK
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he spark is designed to get students thinking about the unit’s topics and
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to generate curiosity and discussion.
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Magnets
UNIT GUIDE
Materials
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1 small magnet
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piece of thin cardboard (a file folder cut in half works well)
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assortment of magnetic and nonmagnetic items (for example, coins, paper
clips, yarn, aluminum foil, toothpicks, paper, scissors, metal washers)
Activity
Begin with a “magic” demonstration. Hold a magnet behind a piece of thin
cardboard so students can’t see it. Make a paper clip cling to the side of the
cardboard opposite the magnet and in view of the students. Show everyone
that the paper clip doesn’t fall off, even if you shake the cardboard! Ask
students what might be holding the paper clip in place. After several guesses,
begin to move the magnet so the paper clip moves, too. Ask students what
they think is making the paper clip move.
Explain that a magnet is holding the paper clip in place, and show students
the magnet. Explain that magnets can hold onto certain things, even through
a sheet of cardboard.
Now allow pairs of students to try the “magic” themselves. Let them explore
fun ways of moving the paper clip without touching it. For example, they
might tilt the cardboard like a ramp and make the paper clip stop sliding
down it by placing the magnet on the other side. After using the magnet and
paper clip, have two pairs of students share their magnets and try using one
magnet to move another through the cardboard. Also encourage them to
find out whether the magnet can move any of the other objects, either with
or without the cardboard barrier.
Below are questions to spark discussion.
What makes the paper clip stick to the magnet, even through the cardboard?
What happened when you tried moving one magnet with another magnet?
How was it different from trying to move the paper clip?
Which other object was most attracted to the magnet?
Why didn’t some of the objects stick to the magnet?
Use this activity to begin an introductory discussion about magnets and
magnetism. Explain that magnetism is a natural force that can move certain
metal objects, sometimes without even touching them. Only certain things
are magnetic, which means a magnet will pull them. Throughout the unit,
students will learn more about magnets.
Many of the unit’s vocabulary terms are related to the spark activity and can
be introduced during the spark. For vocabulary work, see the Vocabulary
section in this Unit Guide.
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Magnets
UNIT GUIDE
PRIOR
KNOWLEDGE
I nvite students to explain their understanding of magnets and their
experiences with magnets.
Probing Questions to Think About
Use the following questions to have students begin thinking of what they
know about magnets.
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ow do you use magnets at home? In school?
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What are some things that magnets pull on?
What are some things that magnets do not pull on?
How do two magnets behave when they are near each other?
How do you think magnets can move objects without touching them?
How are magnets related to electricity?
What is the strongest magnet you have ever seen? What was it used for?
Tell students they will learn more about these topics soon.
UNIT MATERIALS Each unit provides a wide variety of resources related to the unit topic.
Students may read books and other passages, work in groups to complete
hands-on experiments and investigations, discuss science ideas as a class,
watch videos, complete writing tasks, and take assessments.
Resources are available for printing or projecting, and many student
resources are also available for students to access digitally on
.
Selected unit resources are available in more than one language.
For a complete list of materials provided with the unit, see the Magnets
unit page on the Science A–Z website.
VOCABULARY Use the terms below for vocabulary development throughout the unit.
Cut or Fold
Magnets
Magnets
attract
(verb)
to pull something closer
WORD CARD
DEFINITION CARD
✄
Magnets
Magnets
compass
(noun)
a tool with a needle that
always points north, used
for showing direction
WORD CARD
DEFINITION CARD
✄
Magnets
Magnets
core
(noun)
WORD CARD
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They can be found in boldface in the Nonfiction Book, the Quick Reads,
and/or other unit resources. These terms and definitions are available
on Vocabulary Cards for student practice. Additional vocabulary lists are
provided in the teaching tips for Investigation Packs and FOCUS Books.
the center of something,
such as Earth or a
piece of fruit
DEFINITION CARD
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Core Science Terms
These terms are crucial to understanding the unit.
attract
to pull something closer
electricity
a form of energy made when tiny parts move around
in an atom; energy that can power many devices
force
a push or a pull
iron
a strong, hard, silver-gray metal
lines of force
i nvisible lines of magnetic force that flow through and
around a magnet
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Magnets
UNIT GUIDE
magnet
a piece of metal that attracts other pieces of metal
magnetic field
an area around a magnet where magnetic force can be felt
magnetism
a force that pushes and pulls certain metals
metal
a material, usually hard and shiny, that lets electricity and
heat move through it
poles
t wo opposite parts of something, such as the two ends
of a magnet
repel
to push something away
Other Key Science Terms
The following vocabulary is not essential for comprehending the unit
but may enrich students’ vocabulary.
compass a tool with a needle that always points north, used for
showing direction
core the center of something, such as Earth or a piece of fruit
electromagnet a magnet that can be turned on or off and is made
by sending electricity through metal
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electrons t iny parts that move around in an atom and can make
electricity
lift to move something to a higher level
motor a machine that uses electricity to make something move
or work
MRI machine a device that uses a magnetic field to make computer
images of the inside of a person; magnetic resonance
imaging machine
nail a pin-shaped piece of metal used to hold materials together
north pole the end of a magnet where lines of force flow out
pull to use force to move something closer
push to use force to move something away
south pole the end of a magnet where lines of force flow in
spin to move in circles
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Magnets
UNIT GUIDE
Vocabulary Activities
Nam e
__________
MAGNETS
__________
__________
__________
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3
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You may choose to introduce all the terms that will be encountered in the
unit before assigning any of the reading components. Vocabulary Cards with
the key science terms and definitions are provided. Dots on the cards indicate
the reading levels of the Nonfiction Book or the Quick Reads in which each term
can be found. If all level dots appear, the term may come from another
resource in the unit. Students can use these cards to review and practice the
terms in small groups or pairs. The cards can also be used for center activity
games such as Concentration.
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© Learning
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A–Z All
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with its and definitions
definition.
with stude
nts.
The Word Work activity sheets offer fun puzzles and practice with key
vocabulary terms from the unit. For further vocabulary practice and
reinforcement, you can choose from the vocabulary Graphic Organizers.
To build customized vocabulary lessons with terms related to the topic,
see
.
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Credit:
© Learning
Have them
draw
www.scie
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Students can use the Word Smart vocabulary Graphic Organizer to organize
information on the science terms. You may want to assign each student
one to three words to share his or her Word Smart knowledge with classmates.
Students who have the same word should first compare their Word Smart
sheets with each other and then report to the larger group.
The science terms can be used in oral practice. Have students use each
term in a spoken sentence.
As students read, encourage them to create a science dictionary by recording
new vocabulary terms and definitions in their SAZ Journal.
BACKGROUND and Use this section as a resource for more background knowledge on unit
MISCONCEPTIONS content and to clarify the content for students if misconceptions arise.
Refer to Using the Internet below for more ways to extend the learning.
MAGNETS
Written by Katherine Follett
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Q: Do magnets attract all metals?
A: No. Only certain metals are attracted to magnets; these include iron, cobalt,
and nickel. Combinations of metals, called alloys, that contain these metals may
also be magnetic. Other metals, such as aluminum, copper, silver, and gold,
are not magnetic. Most coins, for example, are made of nonmagnetic metals.
Q: Are bigger magnets stronger than smaller ones?
A: Generally yes, but not always. A larger magnet made from the same
material and shaped in the same way as a smaller one will be stronger.
But magnets made of different materials have differing degrees of magnetic
force. For example, “super magnets” are made from neodymium, boron,
and iron. A smaller super magnet has a stronger pull than a much larger
common magnet. Additionally, an electromagnet may be stronger than
a regular magnet of similar size.
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Magnets
UNIT GUIDE
Q: Can anything other than metal be turned into a magnet?
A: Yes. While magnets made of metal are by far the most common, the
electrons in certain other materials can be rearranged to make them magnetic.
Examples include plastic, rubber, and ceramic magnets. However, it takes
special circumstances for nonmetallic items to be magnetized, so these types
of magnets are unlikely to occur in everyday life.
Q: Are the poles of magnets named after Earth’s North and South Poles?
A: No. In each case, the north and south ends are called poles because
that term refers to two points at opposite ends of an object. But Earth
and magnets do have something in common. Earth has a huge magnetic
field with a north and a south pole, just as any magnet does.
Q: What is the difference between Earth’s two kinds of north poles? Which one
does a compass needle point to?
A: The geographical poles represent the ends of the vertical axis around
which the planet rotates. The magnetic poles are the ends of the vertical
axis through Earth’s magnetic field. Earth’s geographical poles do not
change much, but its magnetic poles are constantly on the move. (In fact,
Earth’s so-called North Pole is currently a south magnetic pole, based on
the flow of the magnetic lines of force.) Over many years, the magnetic
poles can migrate and have even been known to switch places. Scientists
determine their historical locations based on geological research into the
alignment of electrons in magnetic rocks.
To accurately use a compass, it is important to account for the difference
between the present location of magnetic north and Earth’s geographical
North Pole. While a compass always points to magnetic north, people are
likely more interested in knowing which way true (geographical) north is,
in order to set a course on a map or toward a known destination. (Earth’s
migrating magnetic poles have been known to cause problems for airports.
Runways have had to be relabeled because pilots rely on Earth’s magnetic
field to navigate in the proper direction during landings.)
Q: Is a magnetic field really just a group of lines? Could a magnetic item “dodge”
the magnetic force if it were placed between some of those lines?
A: While magnetic fields are often shown in diagrams as being made up
of lines, they actually encompass a continuous area surrounding a magnet.
When iron filings position themselves in lines around a magnet, we see how
the magnetic field affects the filings. It turns each filing into a tiny magnet,
and since magnets are attracted to opposite poles and can repel one another,
the filings line up. But the actual magnetic field is just that—a field. The
term lines of force helps describe the field and the direction of force.
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Magnets
UNIT GUIDE
Q: Are electricity and magnetism the same thing?
A: No, but the two are related. Magnetism and electricity are fundamentally
two manifestations of the same force—electromagnetism. But in practice,
they behave differently. Magnetism is a force that can help generate electricity.
When magnets spin around wires, they cause charged particles to flow
through the wires. This process generates an electric current. Other wires
carry the current to homes and businesses. Meanwhile, electricity can also
create magnetic fields. If you wrap a wire around a piece of metal and
pass an electric current through it, a magnetic field forms. If you turn off
the electricity, the field disappears. While electricity and magnetism work
together and are aspects of the same force, they are not the same.
Q: Doesn’t attract mean something else?
A: We do sometimes say that one person attracts another, meaning that
someone thinks the person has good looks and/or a good personality. This
context is similar to saying that a magnet attracts certain objects because,
in both cases, one thing or person draws other things or people closer to
it. Interestingly—like magnets—people can also repel (or be repulsed by)
each other. We sometimes even say that a person has a magnetic personality,
meaning that others want to be near or befriend him or her. These terms
are used in other similar contexts as well. Sugary foods can attract ants.
Armies can repel an enemy. However, in this unit, attract and repel refer
solely to magnetism as a physical force.
© Jupiterimages Corporation
EXTENSION
ACTIVITIES
Using the Internet
Most search engines will yield many results when the term magnet or
magnetism is entered. You can also search for information on a specific
use of magnets or a certain type of magnet. Be aware that some sites
may not be educational or intended for the elementary classroom. More
specific inquiries are recommended, such as:
n
n
n
n
What is magnetism?
magnetic metals
magnetic north pole
magnet arts and crafts
n
n
n
n
magnetic field
Is a(n) _______ magnetic?
magnets in toys
electromagnets
Below are some links with excellent resources for students and/or teachers.
PBS offers a number of fun and informative Curious George videos on
science topics, including one about magnets. Scroll through the topics
to find the “Magnets” video. www.pbs.org/teachers/connect/resources/5721/preview
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Magnets
UNIT GUIDE
A New Zealand site called Science for Kids offers several interactive online
simulations involving magnets and springs.
www.sciencekids.co.nz/gamesactivities/magnetssprings.html
The Discovery website howstuffworks includes a section called How Magnets
Work. It provides a mix of introductory and advanced background
information on magnets and how they work. It also includes a section that
addresses magnet myths. http://science.howstuffworks.com/magnet.htm
This website on magnetism, supported by NASA, provides a good overview
for teachers, including information on the history of magnets.
www-istp.gsfc.nasa.gov/Education/Imagnet.html
The Nondestructive Testing Resource Center covers magnetism in detail.
It contains images and interactives that explain magnetism and show
numerous ways magnets are used. This site is appropriate for teachers
who want to explore the topic in greater depth.
www.ndt-ed.org/EducationResources/HighSchool/Magnetism/magnetismintro.htm
Projects and Activities
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Project: Students can use the magnets and cardboard from the spark
activity to make a magnetic puzzle or game. For example, they might
draw a bird’s-eye view of roads through a town on the cardboard.
They can draw a small car on another piece of cardboard, cut it out,
and glue it to a magnet or a piece of magnetic metal. Then they can
use another magnet on the underside of the cardboard to move the
car through the course.
Arts: Let students use magnets to paint pictures. Working in pairs, have
one student hold a piece of thin cardboard still while the other operates
the magnet. They should put a small amount of paint (tempera or other
thin paint) on the surface of the cardboard and place a screw, washer,
paper clip, or other small magnetic object in the paint. The painter uses
a magnet beneath the cardboard to move the object and create designs.
Encourage students to experiment with shapes and colors.
Field Trip: Tour a power plant to see electric generators—and the
magnets that get the current flowing—in action.
Guest: Invite an electrician or someone who repairs appliances to
explain how magnets are used to generate electricity inside motors,
using tangible models.
Physical Education: Get students moving in a game based on the way
magnets behave. Select two students to jog toward each other in an
open space. Before they reach each other, call out “north and south,”
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Magnets
UNIT GUIDE
n
n
n
n
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“north and north,” or “south and south.” If you call out opposite poles
(north and south), students should run together and join hands. If you
call out the same two poles (north and north or south and south),
students should veer away from each other. You might also use chalk
to sketch a magnet and its lines of force on a basketball court, and then
hold relay races along those lines.
Home Connection: Ask students to take an inventory of magnets
in their home. Appliances with motors include hair dryers, blenders,
mixers, refrigerators, and clocks. Cars, lawn mowers, and power tools
also contain magnets. Electronics such as computers, MP3 players,
headphones, and speakers do, too. Don’t forget the refrigerator magnets.
Students may be surprised at how many magnets are in their homes.
Literature: Good books for kids about magnets include What Makes
a Magnet? by Franklyn M. Branley and What Magnets Can Do by
Allan Fowler.
Writing: What would it be like to be able to use your body as a magnet?
Have students write a pro-con composition about what it might be like
to possess this ability. See
for extensive writing instruction.
Research/Home Connection: Students can conduct
research as a family/home project or in the library/
media center to extend the learning about a topic
in one of the Quick Reads or other unit resources.
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